Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UMass geologist leads team probing Bering Land Bridge

16.08.2002


Researchers from Woods Hole, Scripps oceanographic institutes sail on new Coast Guard ice breaker to study climate, ocean changes



A University of Massachusetts Amherst geoscientist is part of a team of researchers sailing the Bering and Chukchi seas this summer, searching for clues about the sea floor history and the land bridge that once existed between what is now Alaska and Russia. The team will also explore how the disappearance of the land bridge may have affected that region’s climate. Julie Brigham-Grette and colleagues Lloyd Keigwin of Woods Hole Oceanographic Institute and Neal Driscoll of the Scripps Institution of Oceanography are conducting the research in two separate missions on the U.S. Coast Guard Cutter Healy, an ice-breaking vessel. The project is funded by the National Science Foundation’s Office of Polar Programs and is the first coring program on the new ice breaker. The Healy is 420 feet long, or nearly 1.5 times the length of a football field and nearly eight stories high. This summer is the first official science cruise of the ice breaker in American waters.

The five-month mission of the USCGC Healy to the Bering and Chukchi Seas, which includes two other research projects, will mark one of the most comprehensive scientific deployments ever conducted by a Coast Guard icebreaker, said Brigham-Grette. The team is doing a high-tech, seismic mapping of the area’s ocean floor and its shallow sediments, then taking core samples of the sediments. The science team recently returned from the Bering Sea but will reoccupy the ship Aug. 26-Sept. 17 for work in the Chukchi Sea.


"We want to know how quickly the land bridge formed or was flooded with changes in global sea level, cutting off the migration of people and a wide range of plants and animals," said Brigham-Grette. "And we’re looking at the area’s climate history to understand how the ocean and the atmosphere affected the land, and what happened to the watermasses in the region when the land bridge was submerged," she said. "It’s scientifically exciting because it’s interdisciplinary between the three of us as principal investigators. It’s like putting a puzzle together; with each scientist contributing a different but important puzzle piece."

Brigham-Grette’s expertise is in culling ancient climate records from clues embedded in land, lake, and ocean sediment samples going back tens of thousands of years. Keigwin is an expert at interpreting changes in the temperature and water chemistry of ocean water masses and how these changes are related to past climate change using fossils and ocean sediments. Driscoll specializes in interpreting the layering and displacement of rock and sediments, especially in the distribution of sediments in basins and on continental shelves using geophysics.

Brigham-Grette notes that the Bering Strait has actually been submerged dozens of times, as the glaciers approached and retreated. The submerged subcontinent is known as Beringia. The scientific team hopes to gain an understanding of the paleooceanographic history of the region since the last submergence of the strait, at the end of the last Ice Age, some 20,000 years ago.

When the glaciers melted and the sea level rose, seawater drowned ancient rivers and tundra, creating salty estuaries, Brigham-Grette explained. The seismic exploration led by Driscoll and his students in the Chukchi Sea will locate channels where freshwater rivers once ran, and sediment cores drilled in those areas should offer clues to how quickly the sea level rose. Clues in the layers of deposited mud and silt include fossils and the remains of microscopic plants and animals, such as diatoms (made of silica) and foraminifera (made of carbonate). UMass Amherst graduate student Zach Lundeen, and Woods Hole researchers working with Keigwin will be analyzing the sediments and fossil remains.

"We know the climate was different here back then," said Keigwin. "We hope we can learn how different it was, and how the ocean and atmosphere responded to change. In addition to marine sediments, we hope to get samples of the soils and vegetation that existed on the land bridge. We should be able to learn a lot about how things changed here over time by examining the entire region as an environmental system."

"We are thrilled with the performance of the Healy because this was the first cruise to seismically map the Bering Sea and obtain high resolution sediment cores through the Holocene," said Jane Dionne, program manager for the Arctic Natural Sciences, part of the Office of Polar Programs at the NSF. "This research should greatly advance our understanding of the region and should provide important answers to old questions about the role of the North Pacific in the world circulation system, especially during the past glacial periods."

There is much to be learned about how the Earth works by studying climate change recorded in layers of sediment in the past, says Brigham-Grette. "It’s as if the Earth and its oceans have already run a number of natural experiments in global change for us. It’s our obligation now to read the results of these experiments in the sediments, so that we can use this information to predict the nature of climate change into the future."


Note: Julie Brigham-Grette can be reached at 413/545-4840 or juliebg@geo.umass.edu until Aug. 24.

Elizabeth Luciano | EurekAlert!
Further information:
http://www.geo.umass.edu/beringia/index.html
http://www.uscg.mil/pacarea/healy/

More articles from Earth Sciences:

nachricht NASA eyes Pineapple Express soaking California
24.02.2017 | NASA/Goddard Space Flight Center

nachricht 'Quartz' crystals at the Earth's core power its magnetic field
23.02.2017 | Tokyo Institute of Technology

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New pop-up strategy inspired by cuts, not folds

27.02.2017 | Materials Sciences

Sandia uses confined nanoparticles to improve hydrogen storage materials performance

27.02.2017 | Interdisciplinary Research

Decoding the genome's cryptic language

27.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>